This invention relates to newly identified polypeptides and polynucleotides encoding the polypeptides; variants and derivatives of the polypeptides and polynucleotides; agonists and antagonists of the polypeptides; and uses of the polypeptides, polynucleotides, variants, derivatives, agonists and antagonists. In particular, in these and in other regards, the invention relates to polypeptides and polynucleotides encoding polypeptides which are ligands for the neuropeptide receptor HFGAN72, hereinafter referred to as xe2x80x9cHFGAN72 receptor ligandsxe2x80x9d.
This invention relates to newly identified polynucleotides, polypeptides encoded by such polynucleotides, the use of such polynucleotides and polypeptides, as well as the production of such polynucleotides and polypeptides. More particularly, the polypeptides of the present invention are ligands for a human 7-transmembrane receptor. The invention also relates to inhibiting or activating the action of such polypeptides.
It is well established that many medically significant biological processes are mediated by proteins participating in signal transduction pathways that involve G-proteins and/or second messengers, e.g., cAMP (Lefkowitz, Nature, 1991, 351:353-354). Herein, these proteins are referred to as proteins participating in pathways with G-proteins or PPG proteins. Some examples of these proteins include the GPC receptors, such as those for adrenergic agents and dopamine (Kobilka, B. K., et al., Proc. Natl Acad Sci., USA, 1987, 84:46-50; Kobilka, B. K., et al., Science, 1987, 238:650-656; Bunzow, J. R., et al., Nature, 1988, 336:783-787), G-proteins themselves, effector proteins, e.g., phospholipase C, adenyl cyclase, and phosphodiesterase, and actuator proteins, e.g., protein kinase A and protein kinase C (Simon, M. I., et al., Science, 1991, 252:802-8).
For example, in one form of signal transduction, the effect of hormone binding is activation of the enzyme, adenylate cyclase, inside the cell. Enzyme activation by hormones is dependent on the presence of the nucleotide GTP. GTP also influences hormone binding. A G-protein connects the hormone receptor to adenylate cyclase. G-protein was shown to exchange GTP for bound GDP when activated by a hormone receptor. The GTP-carrying form then binds to activated adenylate cyclase. Hydrolysis of GTP to GDP, catalyzed by the G-protein itself, returns the G-protein to its basal, inactive form. Thus, the G-protein serves a dual role, as an intermediate that relays the signal from receptor to effector, and as a clock that controls the duration of the signal.
The membrane protein gene superfamily of G-protein coupled receptors has been characterized as having seven putative transmembrane domains. The domains are believed to represent transmembrane xcex1-helices connected by extracellular or cytoplasmic loops. G-protein coupled receptors include a wide range of biologically active receptors, such as hormone, viral, growth factor and neuro-receptors.
G-protein coupled receptors have been characterized as including these seven conserved hydrophobic stretches of about 20 to 30 amino acids, connecting at least eight divergent hydrophilic loops. The G-protein family of coupled receptors includes dopamine receptors, which bind to neuroleptic drugs used for treating psychotic and neurological disorders. Other examples of members of this family include, but are not limited to, calcitonin, adrenergic, endothelin, cAMP, adenosine, muscarinic, acetylcholine, serotonin, histamine, thrombin, kinin, follicle stimulating hormone, opsins, endothelial differentiation gene-1, rhodopsins, odorant, and cytomegalovirus receptors.
Most G-protein coupled receptors have single conserved cysteine residues in each of the first two extracellular loops, which form disulfide bonds that are believed to stabilize functional protein structure. The 7 transmembrane regions are designated as TM1, TM2, TM3, TM4, TM5, TM6, and TM7. TM3 has been implicated in signal transduction.
Phosphorylation and lipidation (palmitylation or farnesylation) of cysteine residues can influence signal transduction of some G-protein coupled receptors. Most G-protein coupled receptors contain potential phosphorylation sites within the third cytoplasmic loop and/or the carboxy terminus. For several G-protein coupled receptors, such as the b-adrenoreceptor, phosphorylation by protein kinase A and/or specific receptor kinases mediates receptor desensitization.
For some receptors, the ligand binding sites of G-protein coupled receptors are believed to comprise hydrophilic sockets formed by several G-protein coupled receptor transmembrane domains, said socket being surrounded by hydrophobic residues of the G-protein coupled receptors. The hydrophilic side of each G-protein coupled receptor transmembrane helix is postulated to face inward and form a polar ligand binding site. TM3 has been implicated in several G-protein coupled receptors as having a ligand binding site, such as the TM3 aspartate residue. TM5 serines, a TM6 asparagine and TM6 or TM7 phenylalanines or tyrosines are also implicated in ligand binding.
G-protein coupled receptors can be intracellularly coupled by heterotrimeric G-proteins to various intracellular enzymes, ion channels and transporters. See Johnson et al., Endoc. Rev., 1989, 10:317-331. Different G-protein xcex1-subunits preferentially stimulate particular effectors to modulate various biological functions in a cell. Phosphorylation of cytoplasmic residues of G-protein coupled receptors have been identified as an important mechanism for the regulation of G-protein coupling of some G-protein coupled receptors. G-protein coupled receptors are found in numerous sites within a mammalian host.
Over the past 15 years, nearly 350 therapeutic agents targeting 7 transmembrane (7 TM) receptors or their ligands have been successfully introduced onto the market. This indicates that these receptors and their ligands have an established, proven history as therapeutic targets. Clearly, there is a need for identification and characterization of further receptors and ligands which can play a role in preventing, ameliorating or correcting dysfunctions or diseases, including, but not limited to, infections such as bacterial, fungal, protozoan and viral infections, particularly infections caused by HIV-1 or HIV-2; pain; cancers; anorexia nervosa; bulimia; cachexia; obesity; diabetes; asthma; Parkinson""s disease; both acute and congestive heart failure; hypotension; hypertension; urinary retention; osteoporosis; angina pectoris; myocardial infarction; ulcers; asthma; allergies; benign prostatic hypertrophy; chronic renal failure; renal disease; impaired glucose tolerance; sexual dysfunction and psychotic and neurological disorders, including anxiety, schizophrenia, manic depression, delirium, dementia, severe mental retardation and dyskinesias, such as Huntington""s disease or Gilles dela Tourett""s syndrome, among others.
Polypeptides and polynucleotides encoding the human 7-transmembrane G-protein coupled neuropeptide receptor, HFGAN72, have been identified and are disclosed in. U.S. application Ser. No.: 08/846,704, now U.S. Pat. No. 6,020,157, granted on Feb. 1, 2000, and 08/846,705, now abandoned, both of which were filed on Apr. 30, 1997, as well as in WO 96/34877, published on Nov. 7, 1996.
The present invention provides polypeptides and polynucleotides encoding polypeptides which are ligands for the HFGAN72 receptor.
Toward these ends, and others, it is an object of the present invention to provide polypeptides, inter alia, that have been identified as ligands for the HFGAN72 receptor.
It is a further object of the invention, moreover, to provide polynucleotides encoding HFGAN72 receptor ligands.
In accordance with this aspect of the invention, there are provided methods using isolated HFGAN72 receptor ligand polypeptides and nucleic acid molecules encoding these receptor ligand polypeptides, including mRNAs, cDNAs, genomic DNAs and, in further embodiments of this aspect of the invention, biologically, diagnostically, clinically or therapeutically useful variants, analogs or derivatives thereof, or fragments thereof, including fragments of the variants, analogs and derivatives.
It is also an object of the invention to provide an agonist of the interaction of the HFGAN72 receptor ligands and the HFGAN72 receptor.
Another object of the invention is to provide an antibody against the interaction of the HFGAN72 receptor ligands and the HFGAN72 receptor.
A further object of the invention is an antagonist which inhibits the interaction of the HFGAN72 receptor ligands and the HFGAN72 receptor.
It is also an object of the invention to provide a method for the treatment of a patient having need of an HFGAN72 receptor ligand comprising administering to the patient a therapeutically effective amount of the ligand, wherein said patient is suffering from a disease or disorder, including, but not limited to, infections such as bacterial, fungal, protozoan and viral infections, particularly infections caused by HIV-1 or HIV-2; pain; cancers; anorexia nervosa; bulimia; cachexia; obesity; diabetes; asthma; Parkinson""s disease; both acute and congestive heart failure; hypotension; hypertension; urinary retention; osteoporosis; angina pectoris; myocardial infarction; ulcers; asthma; allergies; benign prostatic hypertrophy; chronic renal failure; renal disease; impaired glucose tolerance; sexual dysfunction and psychotic and neurological disorders, including anxiety, schizophrenia, manic depression, delirium, dementia, severe mental retardation and dyskinesias, such as Huntington""s disease or Gilles dela Tourett""s syndrome, among others.
It is another object of the invention to provide a diagnostic process comprising analyzing for the presence of an HFGAN72 receptor ligand in a sample derived from a host suspected of having a disease or disorder, including, but not limited to, infections such as bacterial, fungal, protozoan and viral infections, particularly infections caused by HIV-1 or HIV-2; pain; cancers; anorexia nervosa; bulimia; cachexia; obesity; diabetes; asthma; Parkinson""s disease; both acute and congestive heart failure; hypotension; hypertension; urinary retention; osteoporosis; angina pectoris; myocardial infarction; ulcers; asthma; allergies; benign prostatic hypertrophy; chronic renal failure; renal disease; impaired glucose tolerance; sexual dysfunction and psychotic and neurological disorders, including anxiety, schizophrenia, manic depression, delirium, dementia, severe mental retardation and dyskinesias, such as Huntington""s disease or Gilles dela Tourett""s syndrome, among others.
It is yet another object of the invention to provide a method for identifying compounds which bind to and activate or inhibit the interaction of HFGAN72 receptor ligands and the HFGAN72 receptor comprising contacting a cell expressing on the surface thereof an HFGAN72 receptor, said receptor being associated with a second component capable of providing a detectable signal in response to the binding of the HFGAN72 receptor ligands to said receptor, with a compound to be screened under conditions to permit binding to the receptor; and determining whether the compound binds to and activates or inhibits the interaction of the HFGAN72 receptor ligands and the HFGAN72 receptor by detecting the presence or absence of a signal generated from this interaction. In addition, the ligand can be labeled, for example with 125I, and used in receptor binding assays to identify antagonists or agonists that block binding.
Other objects, features, advantages and aspects of the present invention will become apparent to those of skill in the art from the following description. It should be understood, however, that the following description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications within the spirit and scope of the disclosed invention will become readily apparent to those skilled in the art from reading the following description and from reading the other parts of the present disclosure.